Valve with safety protrusion

ABSTRACT

The present invention is directed to a valve ( 1 ) for a container comprising a grommet ( 2 ) having a plug system ( 10 ) and defining a channel ( 3 ) with an inlet end ( 4 ) and an outlet end ( 5 ) and a stem ( 8 ) slideably arranged in the channel ( 3 ), whereby the grommet ( 2 ) comprises at least two parts ( 7 ) and ( 8 ) sealingly engaged, said first part ( 7 ) having protrusion within said second part ( 8 ).

FIELD OF THE INVENTION

The present invention relates to a new aerosol valve for a pressurizedfluid container, more particularly for one component polyurethane foamapplications.

BACKGROUND OF THE INVENTION

It is known generally known to store fluids under pressure in containers(cans or vessels) in a wide field of applications. The fluids areusually dispensed from the container by means of a valve arranged in acup of the container.

A well-known application is sprayable foams used in both industrialapplications and by hobbyists. As such, containers with sprayable foamcan be exposed to rather extreme conditions in terms of temperature andpressure.

Under these extreme conditions, the pressure in the container may riseand the valve may detach from the container creating potential safetyissues.

In order to prevent the above, several safety measures are used, such asproviding an overpressure relief valve or providing “burst parts” in thecontainer. However, the use of overpressure relief valves is expensive,while providing weakened “burst parts”' in the container is no optionfor containers that are used on building sites as unintended burst ofthe container may be triggered by the nature of use of these containers.

Still, in order to prevent the valve from detaching from the containerdue to overpressure, it is possible to mould part of the grommet overthe container cup. However, the overmoulding is a cost inefficientprocess.

It has now been found that the new valve of the present inventionovercomes the above mentioned drawbacks. In order to prevent the valvefrom detaching from the container due to overpressure, it is possible toincrease the adhesion between the different grommet parts.

The valve according to the present invention is a valve for a container,the valve comprising a cup, a grommet defining a channel with an inletend and an outlet end and a stem slideably arranged in the channel,whereby the grommet comprises at least two parts sealingly engaged, saidfirst part having protrusion within said second part.

In addition, it has been found that the valve is safe and sufficientlyresilient while equally being moisture resistant thereby avoidingstickiness and blockage of the valve.

Use of a valve for a container has already been disclosed in EP1,074,484. The invention describes a valve comprising a plastic cupattached to the opening edge of a pressurized can, comprising a couplingdevice for a can adaptor of a dispensing unit. The plastic cup furthercomprises a plastically deformable, particularly a clinchable,cylindrical pot wall. The coupling device for the can adaptor is formedas an integral connection part. It made of plastics material and isattached via thin connecting webs to the outer edge of the pot wall ofthe valve head. A safety lip is provided to assist in withstandingpressure.

Although the coupling device of the invention comprises a safety lip toassist in withstanding pressure, the inside of the valve is notprotected against rising pressure. If the pressure inside the can risesdue to extreme conditions in terms of temperature and pressure, thegrommet comprising different elements can loosen and the valve candetach from the container. Further, although a thermoplastic materialhas been used to provide hydrophobic properties and avoiddiffusion/absorption of ambient moisture in the container through thevalve, thermoplastic materials exhibit other inconveniences such as“creep”, which is a well known property of thermoplastic (TP) rubbers.This creep allows for the materials to deform and causes the grommet todetach from the cup when the container is put under extreme pressure.

Given the above, the present invention provides a valve for a containerdispensing a pressurized fluid and an assembly applied for dispensing ofpressurized fluids with safety properties, high adhesion properties andsufficient resilience while avoiding the use of an embedding or moldingstep and avoiding the necessity of using of a spring.

In addition, a valve is provided for a container dispensing pressurizedfluids which valve is moisture repellent and therefore will inhibit thewater diffusion and/or absorption that is causing stickiness andblockage of the valve.

None of the prior art discloses the valve according to the presentinvention nor do these documents suggest the presently obtained benefitsassociated therefrom,

SUMMARY OF THE INVENTION

The present invention is directed to a valve for a container, said valvecomprising a grommet having a plug system and defining a channel with aninlet end and an outlet end and a stem slideably arranged in thechannel, whereby the grommet comprises at least two parts sealinglyengaged, said first part having protrusion within said second part.

DESCRIPTION OF THE INVENTION

The present invention is directed to a valve (1) for a container, saidvalve (1) comprising a grommet (2) having a plug system (10) anddefining a channel (3) with an inlet end (4) and an outlet end (5) and astem (6) slideably arranged in the channel (3), whereby the grommet (2)comprises at least two parts (7) and (8) sealingly engaged, said firstpart (7) having protrusion (11) within said second part (8).

An advantage of a valve according to the present invention is thatadditional safety is provided by the design of the grommet. Due to thefirst part of the grommet having a plug system and protrusion withinsaid second part of the grommet, the valve is prevented from detachingfrom the container dome (9) when overpressure occurs inside thecontainer due to extreme conditions in terms of temperature and pressure

Another advantage of a valve according to the present invention is thatby providing a first part of the grommet having protrusion within asecond part of the grommet, additional resilience is provided. Also, byincreasing the contact surface of the first arid second part of thegrommet, additional adhesion and sealing is provided. Furthermore, thedifferent parts of the hydrophobic grommet are dual injected. Due to thetechnique of injecting the different grommet parts, the adhesion betweenthe first and second part of the grommet is guaranteed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically represents a valve according to the presentinvention for a container dispensing a pressurized fluid.

DESCRIPTION OF A PREFERRED EMBODIMENT

Referring to FIGS. 1 and 2, and in accordance with the presentinvention, a valve (1) for a container dispensing a pressurized fluid ispresented, the valve (1) comprising a grommet (2) having a plug system(10) and defining a channel (3) with an inlet end (4) and an outlet end(5), a stem (6) slideably arranged in the channel (3), the grommet (2)comprising a first part (7) provided at said outlet end (5), and asecond part (8) provided at said inlet end (4) characterized in thatsaid first part (7) having protrusion (11) within said second part (8).

The valve (1) is designed to be provided in an opening of a containerdome (9) for controlling dispensing a fluid from said container.According to a preferred embodiment, the valve (1) is designed to beclinched in an opening of a container dome (9). A radially outwardlyextending plug system (10) is provided and will clinch the valve againstthe rim (30) of the container dome (9). The radially outwardly extendingplug system (10) is made of a thermoplastic material, preferablystrengthened with reinforcing additives such as glass fiber. The plugsystem (10) is resilient. The plug system (10) of the grommet (2) issnapped in the opening of the container dome (9) and clinched to the rim(30) of the container dome (9). By means of the plug system (10),additional safety is provided. Due to the first part of the grommethaving a plug system and protrusion within said second part of thegrommet, the valve is prevented from detaching from the container domewhen overpressure occurs inside the container due to extreme conditionsin terms of temperature and pressure.

Said first part (7) of the grommet (2) is preferably made from athermoplastic material, such as polyethylene, polypropylene, polyamide,ABS, POM or PET, preferably reinforced with fillers, such as glassfibre. Use of thermoplastic materials, in particular with the valve (1)comprising at least two parts (7) and (8) sealingly engaged, wherein thefirst part (7) has protrusion (11) within the second part (8), isadvantageously to avoid corrosion, which is experienced when metal cupsare used.

The first part (7) is formed in the shape of a ring, centrally definingthe inlet end (4) of said channel (3). The first part (7) is designed sothat it comprises a plug system (10) for clinching the valve (1) ontothe container rim (30), preferably by means of a radially outwardlyextending part (31). The extending part (31) can be designed as acontinuous ring or, more preferably, as a number of spaced apartradially extending sections (31). As illustrated in FIG. 2, for spacedapart radially extending sections (31) are provided. The shoulderportion (34) of the radially outwardly extending part (31) is providedto be snapped against the container rim (30) and provides additionalsafety so that the valve (1) is hindered to be detached from thecontainer dome (9) when the pressure inside the container rises.

Preferably, the first part (7) further comprises an extended portion(19) which is extendedly injection molded with the plug system (10) ofthe grommet (2). The extended portion (19) is mounted over the rim (30)of the container dome (9) and is preferably designed as a multipurposeconnection ring for a can adaptor of a dispensing unit. At least twoextended legs (33), preferably four, are connected with the extendedportion (19) to reinforce the extended portion (19). In a preferredembodiment, the four extending parts (31) of the plug system (10), theextended portion (19), the four legs (33) are injection moldedsimultaneously and in one piece. The sealing of the first part (7) ontothe container dome (9) may in this way be optimatized. The first part(7) with the plug system (10) has a diameter larger than the innerdiameter of the opening of the container dome (9), so the shoulderportion (34) of the plug system (10) can be plugged against the rim (30)of the container dome (9). As illustrated in FIG. 1 and more in detailin FIG. 3, the inner wall of the first part (7) is provided with ashoulder portion (22) conically shaping the inlet end (4) of the firstpart (7) of the grommet (2).

Another preferred embodiment of the present invention comprises aroundabout extending part (not shown in the figures) as an alternativefor the four legs (33).

The second part (8) of the grommet (2) preferably has a ring formdefining part of said channel (3) and extending from the ring form is aconically shaped wall portion defining the outlet end (5) of saidchannel (3). Said wall portion is preferably defined by the stem (6)having an annular extension (12) provided at a distance of the ringform. in the present embodiment, the ring form of the second part (8) ofthe grommet (2) is adhered to the first part (7) of the grommet (2), Thesecond part (8) of the grommet (2) preferably comprises at least one,and in this case three inwardly extending sealing lips (20).

The first part (7) of the grommet (2) has protrusion (11) within thesecond part (8) of the grommet (2). Said protrusion (11) may increaseadhesion between said first (7) and said second (8) part of the grommet(2). The protrusion (11) of the first part (7) within the second part(8) of the grommet (2) increases the contact surface of both parts andthus the sealing of both grommet parts (7) and (8). More adhesionbetween the two parts (7) and (8) of the grommet (2) prevents the valve(1) of being detached from the container dome (9). Safety in henceincreased. The protrusion (11) of the first part (7) within the secondpart (8) of the grommet (2) prevents the fluid in the container fromcontacting the second grommet part (8), thereby avoiding sticking of thematerial against the inner side of the grommet (2) and hence avoidingblocking of the valve function. Additionally, the radially outwardlyextending plug (10) and the protrusion (11) increase the resiliency ofthe grommet (2) of the valve (1).

According to the present invention, the first (7) and second (8) part ofthe grommet (2) preferably are dual injection molded. Due to thetechnique of injecting the different grommet parts (7) and (8),additional resilience is provided. Furthermore, by providing a dualinjected grommet (2), the adhesion between the first and second part ofthe grommet is guaranteed. The grommet (2) is designed so that theadhesion surface of the different parts (7) and (8) of the grommet (2)is increased. This additional sealing provides a safer alternative forthe valve assembly than the existing valves for pressurized cans,Further, the first part (7) is dual injection molded so that the sealingonto the rim (30) of the container dome (9) is optimized.

The first part (7) of the grommet (2) is preferably manufactured in ahydrophobic thermoplastic material. An advantage thereof is thatpolyurea formed by a reaction of polyurethane and ambient water ingressin the container, will not stick on the first part (7). Hence propersealing of the valve (1) by the stem (6) can be achieved during entirelifetime of the container.

In a preferred embodiment, the first part (7) is made of a thermoplasticmaterial, such as polypropylene or polyethylene, polyamide, ABS, POM orPET, The materials can be strengthened with reinforcing additives suchas glass fibre.

Although these compounds are hydrophobic, they exhibit otherinconveniences such as creep, which is a well known property ofthermoplastic rubber. Therefore, there is a need for an improved grommetwhich is still moisture repulsive but keeps the required snappyproperties of rubber and does not necessarily requires a spring.

According to the present invention, the hardness of the first part (7)is higher than the hardness of the second part (8) of the grommet (2).Preferably, the second part (8) is made of material having a hardness inthe range between Shore A35 and Shore A90, more preferably, betweenShore A70 and Shore A85 and even more preferably a hardness of ShoreA80.

The second part (8) can for example be made of a thermoplasticelastomer, such as styrene-butadiene, butylene-styrene, siliconerubbers, isopropyl ether (Kraton, Shell), chlorinated polyethylene(Tyrin, Dupont de Nemours), epichiorhydrin homopolymers or copolymer,ethylene propylene (Nordel, Dupont de Nemours), fluoroelastomers (Viton,Dupont de Nemours), alcryn MPR (chlorinated olefin interpolymer alloy),Santoprene, Vegaprene, Geolast, Thermolast and Trefsin (AdvancedElastomer Services (EXXON, Elastollan (Elastrogran) In a preferredembodiment according to the present invention, the second part (8) ofthe grommet (2) may act as a spring.

As illustrated in FIG. 1, the stem (6) comprises a disk-shaped base (17)and a conical protrusion extending therefrom, said conical protrusiondefining a dispensing channel (14) with an inlet (14 a) adjacent to saiddisk and an outlet end (14 b) at the distal end of the protrusion. Theinlet (14 a) is defined by holes in the conical protrusion adjacent thedisk-shaped base. The stem (6) preferably comprises a first (15) and asecond (16) disk-shaped resilient lip section, both provided at theouter circumference of the disk-shape base (17). The diameter of thefirst disk-shaped resilient lip section (15) is preferably larger thanthe diameter of the second disk-shaped resilient lip section (16).

In an assembled composition, the stem (6) is inserted into the channel(3) of the grommet (2) whereby the grommet (2) is clamped betweencircular sealing lip (12) at the outlet end (5) and the disk-shaped base(17) at the inlet end (4) of the channel (3). The stem (6) is hereby insealing contact with the inner walls of the channel (3), which sealingis ascertained by, on the one hand the first (15) and a second (16)disk-shaped resilient lip section abutting the conical shoulder portion(22) of the first part (7) of the grommet (2), and on the other hand theannular extension (12) abutting the conical protrusion of the stem (6).

As represented in FIG. 1, the valve is meant to be incorporated in theopening of the rim (30) of the container's dome (9) whereby the innerwall portion of said rim (30) opening is fixedly clamped between thering form (19) and the shoulder portion (34) of the first part (7) ofthe grommet (2), thereby providing a first sealing function. Clearly,the the shoulder portion (34) of the first part (7) of the grommet (2)is positioned in the container. It is further noticed that the firstgrommet part (7) preferably has an outer diameter larger than the innerdiameter of the cup's opening, in order to help preventing the valve (1)from accidentally detaching from the dome (9).

In a preferred embodiment, the second part (8) of the grommet (2) isinjection molded over and along the first grommet part (7). In this way,adhesion between the different grommet parts (7) and (8) is increasedand optimized. The protrusion (11) of the first part (7) in the secondpart (8) of the grommet provides additional sealing and safety.Preferably, the second part (8) of the grommet (2) is injection moldedalong and under the first part (7) and at the sealing surface (13)pressed against the rim (30) of the container dome (9), providing asecond sealing function. As the second part (8) of the grommet (2) ismade of a resilient material, a good sealing can be obtained between thecontainer dome(9) and the grommet (2).

In operation, the stem (6) can be slided between an open and closedposition of the valve (1). In rest, the valve (1) is closed due to thedisk-shaped part (17) of the stem (6) pressing against the shoulderportion (22) of the inner wall of the first grommet part (7). To openthe valve (1), the stem (6) is pushed in a direction towards thecontainer whereby the inlet (14 a) of the dispensing channel (3) is influid communication with the container's inner space. Once the pressureon the stem (6) is released, it will be forced in a closed positionagain by the resilience of the second part (8) of the grommet (2) and bythe pressure inside the container. By means of the protrusion (11) ofthe first part (7) of the grommet (2), the holes at the inlet (14 a) ofthe dispensing channel (3) are located at a distance of the secondgrommet part (8), both in a closed and open position of the valve (1),the fluid in the container will not contact the second grommet part (8),thereby avoiding sticking of the material against the inner side of thegrommet (2) and hence avoiding blocking of the valve function.

According to a preferred embodiment of the present invention and asillustrated in FIG. 1, the second part (8) of the grommet (2) preferablyis dual injection molded onto the first part (7) of the grommet (2) ofthe container dome (9) via a number of injection axes starting from thegrommet (2). In this way, the second (8) part of the grommet (2) isfastened over the rim (30) of the container cup (9). By injectionmolding the second part (8) of the grommet (2) onto the rim of thecontainer dome (9), the safety is increased. When the pressure insidethe container rises, detachment of the valve (1) from the container dome(9) is hence prevented. Furthermore, the adhesion surface between thefirst (7) and the second (8) part of the grommet (2) is substantiallyincreased. Another advantage of molding the second part (8) of thegrommet (2) onto the first part (7) of the grommet (2) at the positionof the sealing surface (13) pressed against the rim (30) of containerdome (9) is that the radially outwardly extending plug (10) and thethermoplastic sealing surface (13) seals the cup (9) on the pressurizedcans without the use of a crimping machine.

Another embodiment according to the present invention provides athermoplastic multipurpose connection ring (19) as intermediateconnection part for easy mounting on the foam applicator, illustrated inFIG. 1. The presence of an external thread (21) assures easy outsidemounting of the foam applicator on the thermoplastic multipurposeconnection ring (19).

According to a preferred embodiment of the present invention, athermoplastic multipurpose connection ring (19) is injection molded asthe extension of the first part (7) of the grommet. Thereby, the valve(1) and the multipurpose connection ring (19) are formed as an integralpart to be mounted on the rim (30) container dome (9), as illustrated inFIG. 1.

In another embodiment of the present invention, the valve (1) comprisesa radially outwardly extended plug system (10) which offers additionalsafety. The plug system (10) is designed as two legs (40) which may beclamped against the inside of the container's cup (9), as illustrated inFIG. 5. Further, the design of this preferred embodiment requires nomechanical clinching process to fasten the valve (1) to rim (30) of thecontainer's dome (9), the valve (1) can thus be assembled without theuse of a clinching equipment thereby simplifying production and reducingproduction cost. Additional seating is obtained by the radiallyoutwardly extending legs (10) of the first grommet part (7) abutting thecontainer dome (9).

According to another embodiment of the invention, the aerosol valve (1)according to the invention can comprise a spring mechanism mounted onthe first part (7) of the grommet (2) to assist the closing of the valveat filling (not shown in the figures).

The prior art grommets have been replaced by a grommet (2) comprising acombination of a first part (7) having a protrusion (11) within a secondpart (8). The protrusion (11) prevents the second grommet part (8) fromcontacting the content of the container. Further, the protrusion (11)increases the adhesion of the first (7) and second part (8) on theinterface. Thereby, the need for an additional process step, such aslaser welding to join both parts together is avoided.

The valve (1) further needs to be moisture resistant. Therefore, thefirst part (7) of the grommet (2) is preferably made of hydrophobicthermoplastic material. Since the chemical components present in thecontainer are moisture sensitive and react with moisture and/or gas toform the final polymer, it should be acknowledged that any contact withambient moisture is to be avoided in order to prevent the forming of thefinal polymer inside the can or vessel. Moisture diffuses via the valvesystem, more particular the rubber grommet in case of gun and tiltingvalves. Additionally, by means of the protrusion (11) of the first part(7) within the second part (8), any contact between the chemicalcomponents in the container and the second part (8) of the grommet isavoided. Water penetration that is causing stickiness and blockage ofthe valve is hence inhibited.

The valve (1) according to the present invention is a new aerosol valvefor pressurized fluid containers, more particularly for One ComponentFoam (OCF) applications, such as polyurethane foam containers, foradhesives and sealants, for food products and for spray paint.

Having described the valve, it is believed that other apparatus and/orcontainers comprising a valve according to the invention will besuggested to those skilled in the art in view of the description set,forth above. It is therefore to be understood that all such apparatusand/or containers are believed to fall within the scope of the inventionas defined in the appended claims.

1. A valve for a container, said valve comprising: a grommet having aplug system and defining a channel with an inlet end and an outlet end;a stem slideably arranged in the channel; wherein the grommet comprisingat least two parts and sealingly engaged, said first part havingprotrusion within said second part.
 2. A valve according to claim 1,whereby the grommet is dual injected.
 3. A valve according to claim 2,whereby a multipurpose connection ring is injected to the grommet duringthe same process.
 4. A valve according to claim 2, whereby the secondpart of the grommet is dual injected onto the first part of the grommet.5. A valve according to claim 1, whereby said part has a hardness higherthan the hardness of said part.
 6. A valve according to claim 1, whereinat least the first part of the grommet is made of a thermoplasticmaterial, selected from polypropylene or polyethylene, polyamide, ABS,POM or PET.
 7. A valve according to claim 6, wherein at least the firstpart of the grommet is reinforced with fillers and/or glass fibers.
 8. Avalve according to claim 7, wherein the second part of the grommet ismade of a thermoplastic elastomer.
 9. A valve according to claim 1,whereby the stem is made of a polyolefine, selected from polyethylene orpolypropylene.
 10. A valve according to claim 9, wherein the stem isreinforced with fillers and/or glass fibers.
 11. A valve according toclaim 1, whereby the stem comprises at least one circular sealing lip.12. A valve according to claim 1, whereby the stem comprises at leasttwo annular resilient lip sections.
 13. An assembly for a containercomprising: a valve as in claim 1; a thermoplastic extended portion;wherein the thermoplastic extended portion, is formed as an integralpart of the grommet.